1. Field of the Invention
The present invention relates to a system for testing a mobile communication apparatus, and a test method therefor and, more particularly, a technique in which in a test system having a sequence measurement function of efficiently performing, according to a measurement sequence created in advance, a test for a mobile communication apparatus including a base station and a mobile terminal such as a mobile phone, or a communication circuit component used for the base station or mobile terminal such as an integrated circuit or a circuit board including it, it is checked whether a series of sequences arbitrarily created is executable, thereby enabling to avoid an inexecutable measurement.
2. Description of the Related Art
Various tests for a mobile terminal represented by a mobile phone and a communication circuit component used for it are conventionally performed by establishing a wireless call connection with a device under test using a pseudo base station apparatus which operates in the same manner as a base station apparatus in a mobile communication network. As an example, Japanese Patent No. 3708458 (which corresponds to KOKAI Publication No. 2003-046431) discloses such a test method. This test method, however, requires a long time to establish a call connection and to perform a control operation, thereby reducing the test efficiency.
To solve this problem, a test system which uses both sequence measurement and measurement using a wired connection control method has been devised. In the measurement using the wired connection control method in the test system, a device under test is directly connected with a cable to be set to a test mode, and is given a command necessary for a test, thereby measuring a signal which is output from the device under test in response to the command. On the other hand, in the sequence measurement in the test system, a measurement sequence as list information including a plurality of measurement items to be executed for a device under test is prepared, transmission/reception tests are sequentially performed for the device under test according to the measurement sequence, and data obtained in a transmission/reception test which corresponds to each measurement item is stored in a memory. When data corresponding to the plurality of measurement items are acquired, the acquired data are read out from the memory, and each item undergoes processing such as analysis processing.
Such a test system can directly control a device under test according to a series of measurement sequences which was created by the user in advance, and automatically acquire data necessary for analysis, thereby allowing a test much more efficient than the conventional method of establishing a wireless call connection and controlling a terminal. Note that a mobile terminal and a circuit component used for it, especially a communication circuit has, in advance, a test mode which supports the test using the wired connection control method.
There are a number of measurement items necessary for delivery inspection which is performed in a production line or the like for a mobile terminal or the like. For example, basic transmission measurement items for a 3GPP W-CDMA terminal include the transmission power of the terminal, a frequency error, an occupied bandwidth, a spectrum emission mask, adjacent channel leakage power, and modulation analysis. In a test for a mobile terminal or the like, a wireless signal transmitted from the terminal is received to obtain data necessary for analyzing each of the transmission measurement items, and the data is read out to analyze each item.
On the other hand, reception measurement items include, for example, bit error measurement for a reception sensitivity test. In the bit error measurement, for example, a terminal is set to a loopback test mode according to the 3GPP standard, and a test system transmits a wireless frequency signal modulated with known data to the terminal. Then, the terminal receives and demodulates the signal, and the test system receives and demodulates the signal which is returned from the terminal, and compares the obtained signal with the known data.
Basic transmission measurement items for a terminal complying with GSM/GPRS as the communication standard which has become widespread in the world include a transmission power, a transmission frequency, a phase error, power versus time (template/mask determination), and an output spectrum. For these measurement items, a signal which is transmitted at a wireless frequency by the terminal is received to obtain data necessary for analyzing each item, and the data is read out to analyze each item. For reception measurement, error measurement for demodulated data which is returned in the loopback mode is main measurement.
For the mobile terminal, there are communication standards such as CDMA2000 1x, CDMA2000 1xEVDO, and LTE in addition to the above standards, and measurement items are defined for each standard.
If measurement is performed using a sequence measurement function in terms of a number of measurement items for such a terminal, the test system executes transmission/reception processing with the terminal at once according to a measurement sequence created in advance, and stores data necessary for analysis in a memory to execute analysis processing. The amount of data acquired in the sequence measurement is mostly determined based on the frequency bandwidth of a transmission signal of the terminal, that is, a frequency bandwidth and an equalization processing count which are determined according to a communication standard. In general, the user can arbitrarily designate these parameters.
Furthermore, since there are different communication standards (W-CDMA, GSM/GPRS, CDMA2000, and the like) for a terminal as described above, and a multi-mode terminal which supports a plurality of different communication standards is recently implemented, it is necessary to perform, for the terminal, unique measurement for each communication standard. Therefore, to simultaneously perform tests for a multi-mode terminal using sequence measurement, the amount of data to be acquired naturally increases.
A list used in sequence measurement can be applied to a test system having a similar function in many cases, and has, therefore, general-purpose use such that the user arbitrarily edits a list used in another test system to use it.
On the other hand, a memory capacity for data storage of the test system is limited. If, therefore, the user sets many measurement items, or makes parameter settings which prolong the measurement time, the total amount of acquired data exceeds the memory capacity for data storage during execution of a series of transmission/reception processes according to a measurement sequence. This results in error measurement or unnecessary measurement for data which have been incorrectly acquired.
In particular, a system with a hardware configuration in which a personal computer creates a measurement sequence, registers it in the sequence memory of a main body by remote control, and then executes it is most likely to perform error measurement or unnecessary measurement due to the above factors.